Combustion engines and particularly diesel engines have a wide variety of applications including passenger vehicles, marine vessels, earth-moving and construction equipment, stationary generators, and on-highway trucks, amongst others. Electronic engine controllers or electronic control modules, ECM, provide a wide range of capabilities which enhance engine operation, tailor engine performance to a particular application or operator, and reduce or eliminate undesirable characteristics typically associated with diesel engines, such as noise, smoke, or difficult starting. One feature which has been provided for various types of engines is the ability to automatically start and/or stop the engine based on various engine or ambient/environmental parameters.
For instance, in any of the above mentioned applications of diesel engines, automatic starting of the engine is desirable to preserve or maintain operating parameters necessary to later assure reliable starting of the engine when the operator intends to use the vehicle, equipment or truck. Automatic starting of the engine can recharge a battery with a depleting power supply, or will maintain engine oil and/or coolant temperatures above pre-established lower limits in cold weather which would otherwise prevent or hinder engine starts.
Moreover, truck owners seek to provide conveniences or amenities for the driver or operator because it is often difficult to attract and retain drivers in a competitive job market. For this application, automatic start/stop features are used to balance the fuel economy interests of the owner while providing conveniences to the driver, such as automatically starting and stopping the engine while the driver is parked to keep the cab temperature comfortable.
Prior to automatic starting of the engine, a series of interlocks or switches, which are monitored by the ECM, must be closed before the engine will start. These switches include a digital input park brake, a hood tilt switch, a transmission in neutral position switch, and a park brake switch. Unfortunately, amongst all of the known automatic engine start enablers, the engine will not be prevented from starting if the fuel level is low (i.e. below a predetermined level). Hence, automatic starting of the engine can run the vehicle or truck out of fuel, which would inadvertently leave the operator and vehicle stranded.